the adsorptive behavior of the immunosuppressive agent tacrolimus was studied by cyclic and differential-pulse voltammetry on a hanging mercury drop electrode (hmde). the drug was accumulated at hmde and two well-defined peak currents were obtained at -1353 and -1417 mv vs . sce (saturated kcl) in borate buffer (ph 10.0) + 0.1 kcl solution. a voltammetric procedure was developed for the determi...

Background: The substitution of hazardous analytical reagents such as Cd with benign alternatives for chemical determination is one of the principles of green chemistry. An eco-friendly Zn reduction method for nitrate determination was developed to achieve this end. Methods: Online zinc reduction-sequential injection analysis (ZnR-SIA) protocol was developed for the determination of nitrogen (N...

PURPOSE Although all contact lenses (CLs) are applied initially to the eye directly from a packaging solution, little is known about the effects of these solutions on human corneal epithelial cells (HCECs). Due to the porous nature of CL materials, they have the potential to sorb components of the packaging solution during storage, which could then be subsequently released upon insertion of the...

A new kinetic method is described for the determination of ultramicro amounts of Cu(II) based on its catalytic effect on the oxidation of trisodium-2-hydroxy-1-(4-sulphonato-1-naphthylazo)naphthalene-6,8-disulphonato (red artificial color PONCEAU 4R) by hydrogen peroxide in borate buffer (B.B.) The detection limit given by Perez-Bendito is 0.8 ng/cm3, but the detection limit that we experimenta...

Event-related potentials (ERPs) were recorded to both predictive (consonant-vowel-consonant) and feedback (picture) stimuli as subjects learned associations between these stimuli. Tbe eonsonantvowel-consonants (CVCs) were selected for lack of emotional content while the pictures (PICs) varied in emotional value (Learning Group; N = 20). A second group of subjects was exposed to the same CVC-PIC...

A capillary electrophoresis method was developed for the analysis of oligosaccharides combined with derivatization with 2-aminobenzoic acid. Glycosaminoglycan delta-disaccharides were effectively resolved on a fused-silica capillary tube using 150 mM borate, pH 8.5, as a running electrolyte solution. This analytical method was applied to the identification of glycosaminoglycan in combination wi...

Spatial compression among the longer DNA fragments occurs during DNA electrophoresis in agarose and non-agarose gels when using certain ions in the conductive buffer, impairing the range of fragment sizes resolved well in a single gel. Substitutions using various polyhydroxyl anions supported the underlying phenomenon as the complexation of Lewis acids to DNA. We saw significant improvements us...

Pharmaceutical preparations usually contain preservatives and sweeteners. When parabens are used as preservatives and a polyol as a sweetener, a transesterification reaction may happen, yielding the transester polyol-paraben. The products formed in the transesterification reaction of methylparaben and sorbitol were analyzed by micellar electrokinetic chromatography and by HPLC. Up to six positi...

Disaccharides tagged with p-aminobenzoic acid (ABA) were separated by capillary electrophoresis (CE) and analyzed on-line with negative ion electrospray ionization tandem mass spectrometry (ESI/MS/MS). The formation of glycosylamine instead of reductive amination was selected as the derivatization reaction. In negative ion ESI, the glycosylamine approach provides more information on linkage and...

Samples of blood and sera were obtained from unrelated adolescent and adult Bantus who were clinical patients at the Central Hospital. Males and females were pooled together for analysis. Hemolysates were analyzed by starch-gel electrophoresis methods using Tris-EDTA-borate buffer at pH 8.6 [1] and by cellulose-acetate electrophoresis in the same basic buffer system. Benzidine was used for stai...